Altman Shakespeare Lamp Contact Problems


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The community theatre where I was recently hired on has a few Altman Shakespeare's that have problems with the lamp sockets. The instruments sometimes "ghost" on and off, and it is evident that there has been some arcing on the lamp posts. Usually if you just take the lamps out, flip them and reinstall them, it will temporarily take care of the problem, but sooner or later it will happen again. These instruments are about 10 years old, so I don't know if it is just time to replace the sockets, or if there is a cheaper way of fixing this. My executive Director suggested using some kind of graphite or a contact cleaner, but I wasn't sure so I thought I would run it by you guys before I go and electricute myself or burn the theatre down. Any suggestions?

THX, Leslie Deal


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Well, since you hired them, I could contact the place that you rented them from, and ask them what they suggest. Odds are they will send you new lights to replace the ones that are not working.


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Graphite is conductive so if you attempt to use it, be very careful about any of it which either as a liquid spray runs out of the socket, or as a powder... not sure what good the powder form would do since it would follow gravity and not apply itself to the walls of the socket. On Lighting Network there was a decent discussion about lamp bases to Sports Lighter fixtures and what chemicals and coatings work well on high temperature lamp bases. While I have high temperature spray on Graphite, I find it more useful for coating the insides of old Altman 360Q lens trains in making them move well. I am not sure I would trust graphite inside of my lamp base.

If a terminal shows arcing, the lamp base will also. Those little arcs prevent good contact with the lamp in forming a high resistance conductor. This resistance adds heat which in turn further melts down the lamp base and lamp's pins. Flipping the lamp over and putting a good pin into a bad socket will as you are doing work for a while in providing at least a cleaner surface area for contact. In this case, the bad part of the lamp base will just start melting thru the fresh pin at the same time as the bad pin than starts to melt thru the good part of the lamp base.

While you can clean the badness of the pins to some degree with a fine emery cloth as long as you than remove the scratches from the surfact with some chrocus cloth which is even finer in grit and don't try to remove anything but what is sticking up above the normal surface. Don't try to remove pock marks and pits because the pin than will be out of round and the larger amount of surface necessary to be removed to get rid of the holes will no longer be in contact with the lamp base. This than will force even more current and thus heat on other parts of the lamp base and pin which still do have a fair amount of contact. Also if your pin gets too small, it won't have good contact with the lamp base which will also cause arcing. I'm not sure how much effort this cleaning of pins will be worth due to the size of the pin and expense of the lamp. There is a nickel plating on the pin which helps prevent oxidation and heat damage to it. Once you sand that coating off or scratch it sufficiently, it will no longer provide a good contact either and probably corrode anyway which will start the problem all over again. There are coatings you can add to re-protect the pin, but to some extent such lamps due to the size of the pin are not worth the effort. A corrode and melted pin is useless, throw the lamp out before it goes into another fixture and destroys it's lamp base. Additional problems with bad contacts would be first heat on the lamp base which could destroy the pinch seal of the lamp in causing it to go bad faster, and the extra heat making the wire feeding the lamp base melt down where it hits the lamp base.

This is also true with the lamp bases. If just oxidation or a bit of charring, the contact might be able to be cleaned with a thinned out cotton swab so it fits into the hole with perhaps some peroxide or electrical contact cleaner applied to it, but the dia. of the pin hole is for the most part too small for much more than that amount of effort. If the lamp base at that point does not become clean, it's time to replace it. There are other tools you can use to clean the base but this should be the simplest in either working or not working. You cannot re-surfact the lamp contact, too small to be working inside of and too small a metal plate you are attempting to work on. By the time you cleaned the surface, the contact's metal would be too thin to resist the heat and current running thru it very long. I do frequently re-surface both lamps and lamp bases of all types but even I don't touch this type of lamp base - too small to work with and not worth the effort.

Fresh lamp bases are very necessary for these fixtures and 10 years is a decent amount of life they have had. Specifically on lamp bases the Altman #97-1580, a high temperature TP-22 base rated for 1,000w/250c in temperature sells for about $16.00 each from sources anywhere from Production Advantage to Altman themselves. Make sure your product has this part number no matter what source it's from because there is three other types of lamp base on the market Altman either sells or used to sell which will be a lot less effective in your fixture.
While Altman recognizes many other brands of lamp base you can get thru other souces - such as those frum Sylvania, Altman, Bender and Wirth, they do not at this point recognize the Ushio C3A lamp base which is often sold as a replacement lamp base for this fixture at a lower cost. The C3A is very popular amongst retailers because depending upon their discount factor with Ushio, the lamp base can be cheaper for them to purchase and in testing by respected users it preforms just as well. However as stated by a engineer at Altman about this lamp base, use of the C3A until such a time as Altman approves it will void the UL listing on this lighting fixture because both Altman does not recognize it in having tested it and the lamp base is itself not UL listed.

The extra $1.35 per lamp base normally the difference between the Altman and Ushio lamp bases is worth the extra cost. At one point I might also have taken apart lamp bases in combining two half good ones into one with good contacts. This was a long time ago and will have by doing so also voided the UL listing on the lamp base. The ETC fixtures are good in that they like an old PAR can's lamp base are designed to come completely apart. Unfortunately however as opposed to the cost for an entire TP-22 lamp base, just the contacts alone from ETC cost that much. The entire lamp base assembly would be more expensive.

One further thing to check is the fixture's plug. Make sure ferrules were used if a stage pin type and that the screws no matter which brand are tight.

I recommend on a stage pin plug that in addition to the 12ga ferrules that you purchase from a electronics supply or McMaster Carr some insulated 16ga ferrules for use with the 12ga ferrules inside the plug. Given the over twice the dia. of a 12ga ferrule on a 16 ga. wire, there is only marginal protection given to the wires above the screw clamping directly onto the strands. Often the 12ga ferrule given the lack of wires will just cut right thru the 12ga ferrule anyway than cut into the conductors anyway. In any case, the screw onto the wires with this size of ferrule will not sufficiently enclose all the wires to the extent that the pressure of the screw will clamp down on all of them to the same amount. Some strands of the wires will have more clamping than others thus a bad connection.

You can fold the wire over on itself by stripping twice the length and folding it back on itself but frequently with heat wire you won't be able to get the fold tight enough.

You can also strip the wire twice as long, than half way up strip the wire again for a 18ga wire in cutting strands, than fold the top part of the wire back on itself. This than often when folded has sufficient amounts of wire to fit with the fold into the 12ga ferrule.

In both cases, it's a question of folding the wire back on itself to act as a filler sufficient in filling up the larger ferrule with wire so that it's full of wire and does not just crush into the conductors.

The easier way to do it as above is with a insulated 16ga ferrule which has a PVC flare out coming off the metal part protecting the area close to where the wire is stripped from shorting to anything. The ferrule itself is proper for the wire but too small to reliably fit into the hole of the plug. Adding the 12ga ferrule as a sleeve over the 16ga ferrule than sleeves the 16ga one sufficient to both fit into the terminal and with the second layer of metal covering the wire, there is little chance that the screw terminal will cut thru one ferrule and than cut into individual strands of the lamp cord.

As always, give a tug to your wires once they are in the terminal to ensure sufficient pressure was put on them. 1/4 turn past finger tight might be an illusion if there was a ding in the screw's threads etc. in being tight in the screw but not tight in the terminal.


We purchased 150 Shakespeares in1997, and soon began having the same problem. I addressed the problem to the rep at the Altman booth at USITT the following March. He told me that the contractors who supplied the sockets failed to apply a final coating to the interior. I asked if there was some way to have the sockets replaced under warrenty. His response was "Do you have any idea how mush that would cost?) I replied that I did because I was having to replace them myself. Obviously, I am still replacing sockets as they die. It was a shame because I had been a loyal Altman user for years because of a great track record with the 360Q. As I said, I am still replacing the TP 220 sockets as they go out. I have also switched to ETC instruments and have not bought anything elso from Altman since then.


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It sounds like you had a completely unrelated issue as the Shakespeares I was working with had already been living 10 years and just needed maintenance. The fact that you are still replacing them in 2012 sounds about right -- even the good ones only lived about ten years on average.

Surprised by your outcome with Altman, fourteen years ago. Did you just take the rep's word for it, or did you talk to someone who had more authority? My experience was that any time there was a factory defect, they replaced parts for free, or maybe you paid for shipping if anything. I seem to remember this about a batch of 1K fresnels that experienced cracked lenses due to missing insulator pads.

Anyway, that does suck. But welcome to the booth.
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I too am surprised by the rep's statement. I've been an Altman dealer coming up on 40 years and they have always gone out of the way to make things "right."


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I thought I'd quickly chime in here- Any time you have arcing at all- immediately replace the socket. You are just going to burn through more lamps if you don't-- and while we LOVE it when you buy more lamps, you'll become more and more frustrated and we don't love that.

Sockets aren't that expensive, and most major lamp suppliers also sell replacement sockets.

Also- sockets change over time. We've improved the contacts and internal design on our lampholders many times over the years. Our current TP 22 and TP 220 XL sockets for G9.5 base lamps are pretty amazing, and far better than what was in the market 10 years ago. They last a lot longer, and have better contacts that actually pinches the pin for the tighter connection, making them last longer and arc less frequently.

Lampholders & Sockets Overview

My suggestion-- The TP220 XL 36" 16 AWG ULSF2- Our Part # 69010 It's 1000W, 250C, 250V rated, and UL Approved.

(I'm not trying to do a sales pitch, just pointing out sockets you can get in the last 6 years are far improved from the ones that originally shipped with the fixtures 10 years ago or more. These improved sockets are used in the current fixtures, so don't base current production on experience from long ago.)
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Does anyone have tips/caveats for changing out these bases? I have done a number of Source 4 changeouts--but never even opened a Shakespeare.


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Should be simple enough in change out in not needing advice on once replacing. Personally, I never got much instruction and espect you won't need it in easy change out.
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KT the TD

Hey all, I have Altman Shakespere Leko's in my catwalks that I use for area lights, I hook two instruments up to one dimmer using 750w lamps. I noticed we were burning through lamps fairly rapidly so I took a peek in the ceramic base and they looked burned in one of the pin holes so I started changing out the ceramics one by one labeling them with the month and year they were replaced so I could track whether that was the true issue or not, so far all has been well until today when my lighting operator for our current show left this lamp photo'd on my desk with a note saying that this came out of an instrument whose ceramic had been changed out in January of this year and it's currently late April.

What are your thoughts? Are ceramics really not meant to last this long and I've just had good luck? Are they wired incorrectly? Is the circuit too hot? As you can tell from the photo there is literally nothing wrong with the filament portion just the pin.

Please help me,

Thank you.


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... What are your thoughts? Are ceramics really not meant to last this long and I've just had good luck?
1. It's a socket, not a ceramic. Some might accept using ceramic to refer to a mogul end prong GX16d as used in PAR64/56, but only/if then.
2. You're not putting bad (used) lamps in good (new) sockets, are you? Arc-ing is like venereal disease; if care is not taken, your entire inventory will become infected.
3. Could the installer not be putting the lamps in correctly? It takes quite a bit of force, especially with virgin sockets, to fully seat a lamp.
4. You shouldn't be using EHG in Shakespeares (or almost, ever). You'll get better performance from GLD/GLE lamps.
5. Sockets should last several years, not months, even with hard usage.
6. If all else fails, try using a different brand of lamp and or socket.
7. Are you using TP22 or TP220 (with heatsink fins) sockets?
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Well-Known Member
looks like a bad socket to me,
you may already know this, but,
"if you have to change out a socket, always put in a new lamp, if the old lamp shows any burn or scorch marks, if you dont you will have the same problem over and over and... "

someone else may chime in with other helpful info...


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Fight Leukemia

KT the TD

Hi all, yes we are replacing the lamps at the same time as the sockets (sorry for the incorrect verbage earlier.) I will look into the GLD/GLE lamps.


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A FWIW, one of the reasons my Shakespeares were "retired" in favor of S4's, was the socket/lamp combo sucks.

Even doing all the things Derek suggested, and I still had major issues with flickering lamps and socket burnout.

Just a heads up that long term, the stated solutions may not solve your problems.

KT the TD

Unfortunately our entire house areas are shakespeares and we have appx 60 instruments. We are also a school district so not so easily funded.


Renting to Corporate One Fixture at a Time.
Can your dimmer handle 2 750w lamps?


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This probably makes no sense, but I was having a similar problem before they changed our dimmer rack. With the old lighting system the fixtures tended to be more on/off, but now that we have more control, lamps are dimmed on/off. We have only had a problem with one fixture (socket changed 3 times) in the last 6 years. I've been curious how that particular fixture is different than the others.


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Hah, reading this thread brought back memories since I'm the one who started it - back before I knew much about failing sockets. Ironically enough, that theatre is still having socket issues, but mostly because they completely fail to maintain their instruments. If anything, they'll replace sockets one at a time which isn't efficient at all. I left as an employee ten years ago but occasionally return as a volunteer. They recently purchased six Altman Phoenix (quartz) ellipsoidals and while they're no Source Four, they're leaps and bounds better than the Shakespeares. They really just need to go dark for a few weeks and do a complete service call. Hahaha I crack myself up.

Anyway, on to the topic. My only thoughts are that any issues with a dimmer would be a red herring unless you were running way, way over-voltage. I would think improper seating of lamps would be a more likely issue. And if fixtures mysteriously stop working, check the connector as well (which is inherently done when you replace a socket as it is).

Still a little confused by @SteveB's complaints about the lamp/socket combo. Maybe it's more of a thermal issue? The setup isn't much different from any other G9.5 arrangement, so I can't imagine why there would be issues unique to only Shakespeares. Unless of course it's something related to the brand of sockets being used. How many companies make the TP-22/TP-220?

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